Refrigerating plant



Sept. 12, 1933. v INDERM'ANN 1,926 286 M REFRIGEMTING PLANT Filad Jiily 9. 1929 fl I MINI) IHIIII In m l ll III NHL!

Source 0F 2 elccfricif Swii'ch Jogrce of" elecfr-iciv Patented Sept. 12, 1933 I i UNITED STATES PATENT orricr.

REFitIGEItATiNG PLANT Erich Kindermann, Berlin-Reinickendorf-West, Germany, assignor to Deutsche Gasgliihlicht- Auer-Gesellschaft m. b. 11., Berlin, Germany,

a corporation of Germany Application July 9, 1929, Serial No. 376,951,

. and in Germany July 24, 1928 6 Claims. (Cl. 62-118) An appropriate cooling of the generatorabwidely varying quantities of heat although the sorber in periodically working absorption refrigdimensions of the outer condensing surfaces are crating plants is very difiicult since, during the rather small. The admission of the refrigerant boiling or generating period the cooling must be is interrupted during the generating period to interrupted, while the quantity of heat'to be the cooling devic of t generator ebsolber- 0 removed during the cooling period fluctuates A mode of execution of the inventi n i hown widely and in addition the temperature of the n the draw n by way of p absorber must be kept as low as possible. The Figure 1 iS a diagrammatic View Of the cooling by means of flowing water is best adapted rangement, d Figure 2 s a diagrammatic V for that purpose owing'to its low temperature of a modification Figure 3 ShOWS in detail a 65 which is below that of the atmosphere and ow- Valve controlling deVieeing to the high capability of absorbing heat with-. In h x p wn in Fi u 1 th in definite ranges-of temperature capable of being eretor absorber of e ri eratin mac ne controlled by the quantity of fluid passing is designated as 2 t0 8 being the Cooling through. But water from a main is not availvice, 2 denoting t evaporator, 3 h Steam p p 70 able everywhere and it will require complex autoto Condenser, 4 the condenser 5 t matic devices for reversing, which will give cause Water tank, the receptacle for pply t to frequent trouble. For that reason it has alrefrigerant a d 7 a check valve vin the ad ready been proposed to cool the absorber by air, sion p p 8 leading to e. v p ator.

, by encasing it for example in a flue and closing At t beginning the heating Period the 75 the exhaust pipe during the heating period. On admission of fluid to the evaporator 2 is interaccount of the low specific heat of the air and its rented y Valve 7 S that the generator W bad heat conducting effect the action of such no longer be cooled- Duri Suc a ing period, cooling is very poor,'that is to say the cooling any qu d i a t Which. at he beginning takes place too slowly, the difference in temperaof uc period Was contained in the jacket con- 80 ture between the air absorbing heat and th stituting the evaporator 2, will be converted into wall of the container radiating the heat being vapors which through the pipe 3 pass to the too great, so that no economical operation is poscondense! the Condensate collecting in the sible. The cooling action, however,-may be inreceptacle 6. Thus during the heating period 0 creased by passing the air past the heat exchangthe jacket or evaporator 2 will contain no llqs5 ing surfaces by means of fans, but by the introuid, but only hot vapors which are a poor conduction of such means fresh sources of trouble will ductor of heat, andthus heat-radiation from the" be created. Thus the drawback of the small generator-absorber 1 to the surrounding air adaptability ofsuch direct cooling by air in rewill be minimized during the heating period, spect of the removal of widely varying quantities which result is desirable from t Point Of w 90 of heat would remain. of thermic efliciency. After the termination of The object of the present invention is an inthe heating period the valve 7 is opened so that direct cooling by air which is almost equal in the liquid refrigerant from receptacle 6 can enter eflect to the cooling by water drawn from the again into the evaporator 2 where it will be 40 main. The method'consists in that a second-reevaporated by absorbing the heat of evaporation 95 frigerant will be introduced in the process of the from the generator-absorber. The vapours flow absorption /machine, which uses the generator through the pipe 3 to the condenser where they absorber or the absorption refrigerating plant will condense while the heat of condensation as evaporator, being condensed in a special conwill be absorbed by the surrounding body of denser, where the heat of condensation is abwater in the tank 5. The condensate flows into 100 sorbed by the air. The condenser and evaporathe receptacle 6 and is returned to the inlet pipe tor of the refrigerating plant are in open com- 8 through the valve 7, thus establishing a. flow munication, so that the pressure of evaporation in a closed circuit. During this cooling period, and condensation is equal, which also accounts the valve 7 being open as Sta r e jacket confor the process being carried through in a cycle st tut n th vap rat 2 wi be fi d w th liq- 105 automatically without the expenditure of work. uid, at least in part as indicated in Figs. 1 and Further the process has been improved in that 2, andsince such liquid is a much better conducthe condenser is placed for instance in a water torof heat than the vapors which filled the evaptank of large heat absorbing capacity, by which orator during the heating period, the radiais attained a high adaptability tr the removal of tion of heat from the/generator-absorber 1. to no the surrounding air, through the exposed outer surface of the evaporator 2, will be promoted during such cooling period, and this again is a desirable result from the point of view of 5 thermic efliciency. If for instance a liquid is employed which will boil at degrees centigrade and about 1 atmosphere of pressure, it is obvious, that up to the cooling down of the absorber from about 130 degrees to about degrees centigrade the cooling of the absorber is eifected more rapidly owing to the enormous withdrawal of heat during the evaporation, than by means of water cooling. There is the drawback, however, that the heat thus withdrawn from the absorber will have raised the temperature of the water in the condenser, so that this temperature will be about 10 degrees above that of the air when using an amount of water such as permitted by practical considerations. As the heat from the water reservoir is transferred only slowly to the surrounding air, the said temperature is the lower limit of the cooling action. Although this limit lies only about 10 degrees below the temperature obtainable by air-cooling and about 10 degrees above that obtainable by,

water-cooling, the process must be considered just as eflicient as water cooling, since the rapid cooling from the final generator temperature to the economical absorber temperature is the.

criterion for an eificient cooling efiect.

In order to effect a further reduction of the lower cooling limitvarious expedients could be applied, for instance a direct air-cooled auxiliary condenser could be arranged for removing the superheat, as well as a likewise direct air-cooled auxiliary cooler for the additional cooling of the condensate collected. This arrangement is shown in Figure 2, where 9 represents the auxiliary cooling device for removing the superheat before condensation and 10 the auxiliary cooling device for cooling after condensation. An improvement. could also be obtained by greatly increasing the surface of the condenser casing by means of ribs or corrugated walls, in order to be able at the termination of the process, when the stronger concentration of the solution in the generator absorber will re quire lower temperatures, to bring the temperature below the said lower cooling limit.

In both constructions illustrated, the evaporator 2 is formed as a jacket surrounding the generator absorber 1; this arrangement is of high efliciency.

The control of the valve '7 is suitably adapted to the control of the source of heat in each particular case. For instance, Figure 3 shows a control of the valve 7 operated electrically. Here 11 is the valve casing, 12 the valve spindle with the valve body or cone, 13 a diaphragm for sealing the chamber around the spindle, against the atmosphere and 14 is a magnet for actua mg the spindle of said valve against the action of a spring 15. -The coil of the magnet is connected with the heating circuit 16 containing the heater coil 17 and requires no special control.

I claim:

1. An apparatus of the class described, comprising a generator absorber, an evaporator associated with said generator absorber, said evaporator being filled with a heat-transferring liquid during the heating period when said generator absorber acts as an absorber, while during the cooling period, when such' generator absorber acts as a generator, the evaporator is filled with vapors of said liquid to insulate the generator and minimize the radiation of heat therefrom a liquidcontaining tank, a condenser coil in said tank to be cooled by the liquid therein, an air-cooled coil the ends of which are connected with the upper portions of the evaporator and of the liquidcooled coil respectively, and another air-cooled coil the ends of which are connected with the lower portions of the evaporator and of the liquidcooled coil respectively.

2. An apparatus of the class described, comprising a generator absorber, an evaporator associated with said generator absorber, said evaporator being filled with a heat-transferring liquid during the heating period when said generator absorber acts as an absorber, while during the cooling period, when such generator absorber acts as a generator, the evaporator is filled with vapors of said liquid to insulate the generator and minimize the radiation of heat therefrom a liquidcontaining tank, a condenser coil in said tank to be cooled by the liquid therein, a conduit connecting the upper portions of the evaporator and of the liquid-cooled coil, and an air-cooled coil the ends of which are connected with the lower portions of the evaporator and of the liquid-cooled coil respectively.

3. An apparatus of the class described, comprising a generator absorber, an evaporator associated with said generator absorber, said evaporator being filled with a heat-transferring liquid during the heating period when said generator absorber acts as an absorber, while during the cooling period, when such generator absorber acts as a generator, the evaporator is filled with vapors of said liquid to insulate the generator and minimize the radiation of heat therefrom a liquidcontaining tank, a condenser coil in said tank to be cooled by the liquid therein, a conduit connecting the upper portions of the evaporator and of the liquid-cooled coil, a return conduit connecting the lower portions of the evaporator and of the liquid-cooled coil, a valve controlling said return conduit, an electrically-controlled heater for the generator absorber, an electrical control device for said valve, and an electric circuit for said heater and said control device, to cause the valve to be closed automatically when the heater is thrown into operation. 4. An apparatus of the class described, comprising a generator absorber, an evaporator associated with said generator absorber, said evaporator being filled with a heat-transferring liquid during the heating period when said generator absorber acts as an absorber, while during the cooling period, when such generator absorber acts as a generator, the evaporator is filled with vapors of said liquid to insulate the generator and minimize the radiation of heat therefrom a liquidcontaining tank, a condenser coil in said tank to be cooled by the liquid therein, a conduit. connecting the upper portions of the evaporator and of the liquid-cooled coil, a return conduit connecting the lower portions of the evaporator and of the liquid-coled coil, a valve controlling said return conduit, means tending to open said valve, an electrical control device for closing said valve, an electrically-controlled heater for the generator absorber, and an electric circuit for said heater and said control device, to cause the valve to be closed automatically when the heater is thrown into operation, and to be opened automatically when the heater is thrown out of operation.

5. An apparatus of the class described, comprising a generator absorber, an evaporator jacket surrounding said generator absorber, the outer surface of said jacket being exposed to a cooling medium, a liquid-containing tank, a condenser coil in said tank, a connection from the upper portion of said jacket to the upper portion of said condenser coil, a valved connection from the lower portion of said coil to the. lower portion of said jacket, said two connections together with said coil and said evaporator jacket forming a closed circuit, and a vaporizable liquid in said circuit, said jacket containing such liquid during the cooling period when the valved connection is open and the generator absorber acts as an absorber, whereby such liquid will promote the transfer of heat from the absorber to the cooling medium which is in contact with the outer surface of the jacket, while during the heating period when the valved connection is closed and the generator absorber acts as a generator, the jacket will be filled with vapors of said liquid to minimize transfer of heat from the generator to the cooling medium which is in contact with the outer surface of the jacket.

6. An apparatus of the class described, comprising a generator absorber, an evaporator jacket surrounding said generator absorber, the outer surface of said jacket being exposed to the surrounding air, a liquid-containing tank, a condenser coil in said tank, a connection from the upper portion of said jacket to the upper portion of said condenser coil, a valved connection from the lower portion of said coil 'to the lower portion of said jacket, said two connections together with said coil and said evaporator jacket forming a closed circuit, and a vaporizable liquid in said circuit, said jacket containing such liquid during the cooling period when the valved connection is open and the generator absorber acts as an absorber, whereby such liquid will promote the transfer of heat from the absorber to the surrounding air which is in contact with the outer surface of the jacket, while duringv the heating period when the valved connection is closed and the generator absorber acts as a generator; the

jacket will be filled with vapors of said liquid to ERICH KINDERMANN. 

